Union nuts & cones?

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gwrdriver
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Joined: Mon Jan 06, 2003 10:31 am
Location: Nashville Tennessee

Re: Union nuts & cones?

Post by gwrdriver » Fri Oct 12, 2018 9:27 am

Greg and all,
Many years ago MSC offered a bewildering array of very reasonably priced "special" taps and dies which included 40-TPI. I began to buy a few, thinking this would be a good way to economically acquire 40TPI "ME" taps and dies, but what I quickly realized was that these US 60° thread form tools wouldn't successfully mate with the 55° thread form of the British ME series.

The thread angle wasn't the problem. I found there would be a fouling at the roots and crest caused by the difference in thread forms, the British threads having rounded root and crest, and the US not. The result was that a fitting could only be run in with fingers about 2 turns before stopping and required force after that. And of course as we all know, if we have to force a mechanism something isn't right. Running a US tap or die over an ME fitting eliminated the fouling.

Of course if you make your own fittings and stick with a single there's no problem, but prospective buyers of Victor's taps and dies (and I'll probably be one) should be aware that they will probably be US thread form and won't be a no-mods match for fittings made with British ME threads.
GWRdriver
Nashville TN

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Greg_Lewis
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Joined: Wed Jan 15, 2003 2:44 pm
Location: Fresno, CA

Re: Union nuts & cones?

Post by Greg_Lewis » Fri Oct 12, 2018 11:36 am

Thanks for the heads-up, gwrdriver. Wouldn't it be nice if the whole world was on one single thread system?
Greg Lewis, Prop.
Eyeball Engineering — Home of non-interchangeable parts.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

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tornitore45
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Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Union nuts & cones?

Post by tornitore45 » Fri Oct 12, 2018 1:28 pm

Victor Machinery is a gem. Fair prices and large assortment.
Mauro Gaetano
in Austin TX

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dnevil
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Location: Springtown, Texas
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Re: Union nuts & cones?

Post by dnevil » Tue Oct 16, 2018 1:26 pm

Dianne,

Here is a short article with drawings for making Union nuts and fittings by Billy Van Brocklin.

http://ibls.org/mediawiki/index.php?tit ... 6_Fittings

Regards,
Daris
Daris Nevil
IBLS Secretary
North American Region
http://www.ibls.org

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